The present invention relates generally to directional or horizontal drilling devices. More particularly, the present invention relates to an electrical transmission line for use with directional or horizontal drilling machines.
Directional or horizontal drilling machines are used to drill holes along a generally horizontal path beneath the ground. After a hole is drilled, the hole is back reamed and then a length of cable or the like can be passed through the hole. Such directional drilling machines eliminate the need for digging a long trench to lay a length of cable or the like.
A typical directional drilling machine includes an elongated track that can be aligned at an inclined orientation relative to the ground. A drill head is mounted on the track so as to be moveable along the length of the track. The drill head includes a drive member that is rotated about a drive axis that is generally parallel to the track. The drive member is adapted for connection to a length of pipe, or drill stem. For example, the drive member can include a threaded end having either female or male threads.
To drill a hole using the directional drilling machine, the track is oriented at an inclined angle relative to the ground, and the drill head is retracted to an upper end of the track. Next, a length of drill stem is unloaded from a magazine and is coupled to the drive member of the drill head. Once the drill stem is connected to the drill head, the drill head is driven in a downward direction along the inclined track. As the drill head is driven downward, the drive member is concurrently rotated about the drive axis. Typically, a cutting element or drilling/boring member, is mounted at the distal end of the drill stem on the drill head. Consequently, as the drill head is driven down the track, the rotating drill stem is pushed into the ground thereby causing the drill stem to drill or bore a hole. By stringing multiple drill stems together, it is possible to drill holes having relatively long lengths.
After drilling a hole, it is common for a back reamer to be connected to the end of the drill string. Once the back reamer is connected to the end of the drill string, the directional drilling apparatus is used to pull the string of drill stems back toward the drilling machine. As the string of drill stems is pulled back toward the drilling machine, the reamer enlarges the pre-drilled hole, and the drill stems are individually uncoupled from the drill string and loaded back into the magazine of the directional drilling machine.
In order to accurately guide the drill string, an operator must monitor the position of the drill head. The principal means for locating the position of the drill head for guiding it is to equip the drill head with an electronic device that emits electromagnetic energy. Typically, the electronic device is a radio transmitter or sonde mounted within the drill head. The sonde emits electromagnetic energy at radio frequencies which can be detected above the ground by an operator using an electromagnetic wave detection device, or the like, tuned to the same radio frequency emitted by the sonde. Accordingly, by providing feedback of the drill head""s position, the drilling machine operator can make the required adjustments such that the hole is bored at the proper depth and in the proper direction.
Electrical power required to operate the sonde has typically been supplied via a conventional wire line, or a battery placed within the drill head. Several problems are associated with the conventional wire line in that it is cumbersome to feed the wire line through the drill stem. In order to extend the drill string, sections of drill stem are added at the drive head of the drilling machine. Therefore, a new length of wire must be spliced or connected to a previous length or wire in the drill string. This takes time and is not generally an efficient process, thus reducing the overall productivity and slowing down the drilling process.
Providing power to the sonde via a battery is problematic in that the energy delivered to the sonde is limited to the energy capacity of the battery. Therefore, the output signal strength emitted by the sonde is practically limited to the battery""s energy capacity. Since electromagnetic waves are emitted from a source (the sonde) beneath the ground, they are greatly attenuated by the time they reach the detection device above ground. Accordingly, it is desirable to increase the energy or power delivered to the sonde to increase the strength of the electromagnetic waves emitted therefrom.
For the foregoing reasons, there is a need for an apparatus, system and method capable of providing electrical power to an electronic device located within a drill head of a drilling machine that greatly enhances the productivity of the drilling process. Furthermore, there is a need for providing power to the electronic device that is not limited by the energy capacity of a battery.
The invention is directed to an apparatus, system and method that satisfies the need identified above. The apparatus, system and method having features of the invention is capable of providing power from an origin above the ground to an electronic device located below the ground. The apparatus, system and method having features of the invention is also capable of providing electrical signals between the origin (above ground) and the electronic device located below ground. Having these capabilities greatly enhances the drilling process, thus making it faster, more reliable and more efficient.
One aspect of the invention relates to a drill head that forms a portion of a drill string for boring a hole through the ground. The drill head has a member that has a generally longitudinally extending housing and includes an outer surface, an inner surface defining a hollow passage therethrough and further defining a chamber, a first end adapted and configured for boring through the ground and a second end adapted and configured to be coupled to a starter rod or a drill stem. An electrically conductive ring is radially disposed about a distal end of the second end and an electrically insulative ring is radially disposed about the second end and located proximate to the electrically conductive ring. An electrical conductor encapsulated by an electrically insulative material is disposed within the hollow passage. The electrical conductor is electrically connectable between the conductive ring and an electronic device disposed within the chamber. The electrically insulative ring provides electrical isolation between the conductive ring and the outer surface of the drill head. The electrically insulative material provides electrical isolation between the electrical conductor and the inner surface of the hollow passage.
Another aspect of the invention relates to a drill pipe that forms a portion of a drill string for boring a hole through the ground. The drill pipe has a member having a generally longitudinally extending housing including an outer surface, an inner surface defining a hollow passage therethrough and first and second ends adapted and configured to be coupled to a second member. The drill pipe also includes first and second electrically conductive rings that are radially disposed about first and second distal ends of the member. The drill pipe also includes first and second electrically insulative rings that are radially disposed about the first and second ends and proximate to the first and second electrically conductive rings and an electrical conductor encapsulated by an electrically insulative material. The electrical conductor is disposed within the hollow passage and is electrically connectable between the first and second conductive rings and the first and second electrically insulative rings. The electrically insulative rings provide electrical isolation between the first and second conductive rings and the outer surface of the starter rod. The electrically insulative material provides electrical isolation between the electrical conductor and the inner surface of the hollow passage.
A further aspect of the invention relates to a drill string for boring a hole through the ground having one end adapted and configured to be coupled to a drilling apparatus. The drill string includes one or more members having generally longitudinally extending housings, each of the housings including an outer surface and an inner surface defining a hollow passage therethrough and first and second ends adapted and configured to be coupled to a drill head, a drill stem or a starter rod. The drill string also includes electrical connection means between each end of the members. Electrical insulation means between the electrical connections and the outer surfaces of each the members and one or more electrical conductors encapsulated by an electrically insulative material, each electrical conductor being disposed within the hollow passage of each of the members and are electrically connected through the electrical connection means to an electrical conductor of an adjacent member throughout the length of the drill string.
Yet another aspect of the invention relates to a drilling apparatus for boring a hole through the ground. The drilling apparatus includes a frame having a longitudinal axis extending from a first frame end to a second frame end, a drill string having a first end adapted and configured to be coupled to the drilling apparatus and a second end adapted and configured for boring a hole through the ground. The drill string further includes one or more adjacently disposed members including electrical connection means disposed therebetween. The electrical connection means provide electrical continuity between the members. The drilling apparatus also includes a drive mechanism mounted on the frame for movement along the longitudinal axis and the drill string is connected to the drive mechanism for the drive mechanism to rotate the drill string and to longitudinally advance and retract the drill string in response to the drive mechanism moving along the longitudinal axis. The drilling apparatus also includes means for providing electrical continuity between a first and second ends of the drill string.
Still a further aspect of the invention relates to drilling apparatus for boring a hole through the ground. The drilling apparatus includes a frame having a longitudinal axis extending from a first frame end to a second frame end, a drill string having a first end adapted and configured to be coupled to the drilling apparatus and a second end adapted and configured for boring a hole through the ground. The drill string further includes one or more adjacently disposed members and signal flow path connection means disposed therebetween. The signal flow path connection means providing signal continuity between the members. The drilling apparatus also includes a drive mechanism mounted on the frame for movement along the longitudinal axis and the drill string is connected to the drive mechanism for the drive mechanism to rotate the drill string and to longitudinally advance and retract the drill string in response to the drive mechanism moving along the longitudinal axis. The drilling apparatus also includes one or more signal flow path means disposed within the drill string. The signal flow path means providing electrical signal continuity between first and second ends of each member and first and second ends of the drill string.
Still another aspect of the invention relates to a method of providing an electrical connection throughout the length of a drill string. The drill string includes one or more members having generally longitudinally extending housings. Each housing member includes an outer surface and an inner surface defining a hollow passage therethrough. The first and second ends of each member are adapted and configured to be coupled to a drill head, a drill stem or a starter rod. The drill string also includes electrical connection means between ends of each of the members and electrical insulation means between the electrical connection means and the outer surfaces of each of the members. The drill string also includes one or more electrical conductors encapsulated by an electrically insulative material and each electrical conductor is disposed within the hollow passage of each of the members and are electrically connected through the electrical connection means to an electrical conductor of an adjacent member throughout the length of the drill string. The method includes moving a first member into coaxial alignment with a drill axis, coupling a second member to the first member and engaging electrical connection means between adjacent ends of the members while coupling the first member to the second member.
Yet another aspect of the invention relates to a system for locating a drill head located below the ground from a location above the ground. The system includes a drilling apparatus, a drill string arranged and configured to be coupled to the drilling apparatus at one end and coupled to a drill head at another end, said drill string further including one or more members having generally longitudinally extending housings, each of the housings include an outer surface and an inner surface defining a hollow passage therethrough and first and second ends adapted and configured to be coupled to a drill head, a drill stem or a starter rod. The drill string also includes electrical connection means between each of the members and electrical insulation means between the electrical connection means and the outer surfaces of each of the members. The drill string also includes one or more electrical conductors encapsulated by an electrically insulative material. Each electrical conductor is disposed within the hollow passage of each of the members and are electrically connected through the electrical connection means to an electrical conductor of an adjacent member throughout the length of the drill string. The system also includes an electronic transmitter disposed within the drill head, the transmitter emitting electromagnetic energy. The system also includes an electronic receiver disposed above ground, the electronic receiver receiving the electromagnetic energy.
Another aspect of the invention relates to a drill head that forms a portion of a drill string for boring a hole through the ground. The drill head includes a member having a generally longitudinally extending housing including an outer surface, an inner surface defining a first hollow passage therethrough. The housing further defining a chamber, a first end adapted and configured for boring through the ground and a second end adapted and configured to be coupled to any one of a starter rod and a drill stem. An electrically insulative ring radially disposed about said second end, and one or more second hollow passages defined through said member, said one or more second hollow passages forming one or more access tunnels for providing a signal flow path.
Yet another aspect of the invention is a drill pipe that forms a portion of a drill string for boring a hole through the ground. The drill pipe includes a member having a generally longitudinally extending housing including an outer surface, an inner surface defining a first hollow passage therethrough and first and second ends adapted and configured to be coupled to a second drill pipe. An electrically insulative ring radially disposed about said second end, and one or more second hollow passages defined through said member, said one or more second hollow passages forming one or more access tunnels for providing a signal flow path.
Still a further aspect of the invention is a drill string for boring a hole through the ground having a first end adapted and configured to be coupled to a drilling apparatus and a second send adapted and configured for boring a hole through the ground. The drill string includes one or more members having generally longitudinally extending housings, each of said housings including an outer surface and an inner surface defining a hollow passage therethrough and first and second ends adapted and configured to be coupled to any one of a drill head, a drill stem and a starter rod. Electrical insulation means between said members, and one or more second hollow passages defined through said member, said one or more second hollow passages forming one or more access tunnels for providing a signal flow path.
Another aspect of the invention is a method for providing an electrical connection between first and second pipes in a drill string, the pipes including electrical conductors that extend through the pipes, the electrical conductors including electrical contact locations attached to the pipes adjacent the ends of the pipes, the electrical contact locations including a first electrical contact location corresponding to the first pipe and a second electrical contact location corresponding to the second pipe, the first and second electrical contact locations being positioned such that when the first and second pipes are threaded together, the first electrical contact location contacts the second electrical contact location. The method including electrically connecting the electrical conductors of the first and second pipes by threading the first and second pipes together thereby causing the first electrical contact location to be brought into contact with the second electrical contact location.
A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.